1. Field of the Invention
The present invention pertains generally to containers, and more particularly to beverage containers and even more specifically to disposable beverage cups.
2. Description of the Related Art, Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Early in the 20th century, people commonly shared glasses or dippers at water sources such as school faucets or water barrels in trains. Obviously, especially at a time when the means to prevent transmission of common ailments were very limited, the shared use of glasses or dippers caused public health concerns. Lafayette College biology professor Alvin Davidson conducted one of the seminal investigations into the shared use of beverage containers. In 1908, Technical World Magazine published Dr. Davidson's study with the sensational title “Death in School Drinking Cups.” Dr. Davidson's findings were based on research carried out in Easton, Pa.'s public schools.
Sharing water sources through shared containers was ultimately banned after the invention of the DIXIE CUP® disposable drinking cup in 1908, when cheap and sanitary disposable cups became available. Early in the development of the disposable cup, it became obvious that they could be very useful in many settings, including hospitals. It was determined that the cost of cleaning glass cups for reuse was almost double than using the disposable cups available at the time.
Originally, paper cups for hot drinks were glued together and made waterproof by dropping a small amount of clay in the bottom of the cup, and then spinning at high speed so that clay would travel up the walls of the cup, making the paper water-resistant. However, that process resulted in drinks smelling and tasting of cardboard. Cups for cold drinks could not be treated in the same way, as condensation formed on the outside, soaking into the board and making the cup unstable. To remedy that shortcoming, cup manufacturers developed the technique of spraying both the inside and outside of the cup with wax.
Both clay-coated and wax-coated cups disappeared with the invention of polyethylene (PE) coated cups. That process covers the surface of the board with a very thin layer of PE, not only waterproofing the board, but also welding the cup's seams together. The modern widely used paper cup is made from natural organic resins such as wood fiber.
Later on the development and use of disposable hot beverage cups, it became important to utilize materials with thermal insulating properties. Accordingly the most commonly used “modern” hot beverage cups are made from two basic materials: (1) expanded styrene resin; and (2) paper.
Expanded polystyrene resin (a synthetic resin produced chemically), known as Styrofoam®, has excellent thermal insulating properties. Further, the cup-wall strength can be controlled at the manufacturing point and varies according to resin density. The Styrofoam® cup's wall strength can be further enhanced by laminating the outside of the cup wall with paper.
Paper cups' low thermal insulating characteristics can also be enhanced by slipping common multi-layered paper insulating sleeves over the outside of the paper cups. At least one of the paper laminations of the sleeve is generally corrugated to create air space between the consumer's hand and the outer surface of the paper cup to increase thermal insulation between hand and cup. The disadvantage of this combination of two paper products is that the sleeve is a loose slip fit that is cumbersome and poses a safety hazard. Even sleeves that are made with a small deposit of thermal activated adhesive on their inner surface fail to effectively and permanently attach the sleeve to the cup.
From the perspective of safely holding a cup containing a hot liquid, Styrofoam cups appear to present the better alternative. At this point in the development of safe, monolithic and thermal insulating cups, the cost of design and production, especially the raw material costs appear to be a major obstacle. It should be noted, however, that there are a number of materials that could be used in high volumes resulting in a commercially viable and affordable thermal insulating cup. The present invention combines the use of materials with optimal thermal insulating properties and costs, and the resulting optimal ergonomic properties.
Ergonomics is defined by Webster as: (1) an applied science concerned with designing and arranging things people use so that the people and things interact most efficiently and safely—also called biotechnology, human engineering, human factors; (2) the design characteristics of an object resulting especially from the application of the science of ergonomics. The present invention comprises a device and method which utilize several available materials and conventional manufacturing and fabrication means, and improvements thereof. The essence of the present invention, therefore, is the fact that it provides the geometrical and physical boundaries for manufacturers to use alternative materials and produce an environmentally friendly, seamless and ergonomically efficient cup. Obviously, the choice of materials is driven by manufacturing and environmental concerns. However, the present invention can achieve a viable, seamless cup with optimal geometrical and ergonomic properties.
There are many reasons for concern by manufacturers, retailers and customers over what is the optimal material for making disposable beverage cups. There is a growing demand for environmentally friendly or “green” disposable materials that are biodegradable or compostable. That demand provides an incentive for innovative materials that could ultimately displace expanded resin as a widely used packaging and container base stock material. Years ago before greenhouse emissions became such a huge concern, public attention was focused on the environmental effect of manufactured materials on the earthen material in and around landfills and on the ground water contaminated by leeching of the buried manufactured materials. Attention to environmental impact, therefore, centered on what happens below the ground surface. It is well known that Styrofoam®, which comprises expanded plastic resin made from nonrenewable crude oil stock, might not decompose thus becoming a waste burial threat in the ground. Common paper cups were not seen as much of a threat to the environment because they eventually decompose when buried in the ground and were biodegradable because they were made from wood pulp containing natural resin or fiber. But then public focus increased dramatically on greenhouse gases being produced and released into our atmosphere above the ground. Now, some experts and public lobby groups are arguing that the manufacture of Styrofoam® and its fabrication into a drinking cup release far less greenhouse gas into the atmosphere than the amount of methane (CH4) produced in the manufacture of a paper cup and in its decomposition when buried in the ground. Volume for volume, methane is one of the greatest threats of all gases when released into the atmosphere, trapping heat and thereby increasing global warming. Because of the mixed bag of advantages and disadvantages, it is hard to predict whether Styrofoam® or paper products will be determined to be the environmentally friendly food container material of choice.
Natural resins processed from corn, banana plant, bamboo, hemp, cotton and recycled paper are emerging alternatives to just wood by itself as a base fiber stock material for fabrication of paper cups. Paper is made from such alternative fibers throughout the world. Paper is recyclable more than once. It is also biodegradable and compostable, so is environmentally friendly. In time, expanded polystyrene could be replaced by expanded (foamed) vegetable fiber that is expanded and stabilized with naturally occurring starches and proteins. There are several nontoxic foaming agents that can expand a fibrous solution. The expanded and stabilized fibrous solution would then dry and solidify within a predictable molding volume. Synthetic resin or natural fiber, flat or expanded, are logical material types that can be formed into the solid, monolithic, seamless geometry of this invention as can any plausible material.
Starting with the rapidly gained popularity and high volume output of the fast-food industry, the need for disposable beverage cups with lids became evident. The inception of drive-up window service usually associated with the fast-food industry made the safe containment of beverages, especially hot beverages, an important requirement. A cup without a lid is potentially unsafe in the pedestrian and vehicular travel modes. The safe manipulation of a beverage cup for drinking without spilling is an important requirement, necessitating a lid. However, there has not been much, if any, significant improvement in the container, i.e., the lid and cup, from the standpoint of the consumer's ability to manipulate and handle the container without spilling the beverage.
A disposable lid for a disposable beverage cup is commonly a flat plastic disc with a skirt around its perimeter. The skirt snap fits onto the top of a beverage cup. Lids comprise either an opening near the perimeter of the lid for drinking directly from the cup or a circular opening in the lid's center through which a straw can be inserted. Some variations, such as hemispherical lids, are also commercially available. However the problem with each variation is the same: the snap fit of the lid over the top of a disposable beverage cup results in the lid's skirt not being flush with the cup. Because the skirt of the lid sticks out from the sides of the beverage cup, there is an increased likelihood of the lid becoming detached from the beverage cup if there is any upward pressure on the lid's ridge. This pressure could come from the consumer's hand, a vehicle's beverage holder or a number of other sources.
A disposable beverage cup without a lid containing a hot beverage such as coffee or tea is a potential safety hazard to the consumer handling the cup and to people and environment around the consumer. However, a disposable beverage cup with a lid affixed to it is equally hazardous if the lid is inadvertently and suddenly detached, causing spillage of hot beverage onto the consumer and possibly onto other people in the consumer's immediate vicinity. Two effects of lid attachment commonly occur: First, the cup is suddenly opened and beverage spillage occurs; and second, the consumer's hand-grip suddenly strengthens on the lidless cup causing it to compress, thereby erupting the beverage out of the cup. The exposed lid skirt can also be inadvertently struck against any object while the cup and lid assembly is in motion for transport from, for example, a store counter to a table or to an automobile in a drive-up service mode.
The present invention solves the problem of lids becoming detached from disposable beverage cups by adding structural characteristics to the cup that guard the lid skirt edge against most inadvertent and accidental lid detachment while providing a means for controlled, safer lid removal from the cup.